Microfabrication of semiconductor chips has become possible with the advances that have been made in semiconductor manufacturing techniques, and SoC (System-on-a-Chip) capable of advanced signal processing has been achieved by mounting analog and digital circuits, interface functions for interfacing various devices and various other functions on one and the same chip.
By way of example, an LSI chip used in a mobile telephone can be mentioned. In an LSI chip intended for a mobile telephone, there are instances where a functional block for controlling wireless communication and a functional block for implementing various applications incorporated in a mobile telephone are mounted on a single chip. In addition to these functional blocks, various functional blocks such as a block for interfacing an external memory device, a functional block for controlling a camera unit and an LCD driver, etc., are mounted on the chip in conformity with customer demand.
By thus mounting a plurality of functional blocks on the same chip, it is possible to reduce occupied area and lower the cost of system manufacture in comparison with the conventional system composed of a plurality of individual chips equipped with the respective functions.
[Patent Document 1] Japanese Patent Kokai Publication No. 62-241365A
[Patent Document 2] Japanese Patent Kokai Publication No. 4-305960